[mythtv-users] prebuffering pause, jittery video

[Kirby Bakken]

I've started to try to 'reverse engineer' the code that results in this 
error...  but some help would save me some time!  :-)

I've got a Biostar T6100-939 MB, a Athlon64 3500+ processor, 1GB memory, 
a 250 GB SATA hard-drive, and a Nvidia 6100 PCIExpress video adapter.  
I'm running a 2.6.13-r4 gentoo kernel, and an HD-5000 DVB HDTV adapter.  
I get 8 or 9 HDTV stations, and they all come in pretty good, but I 
can't watch 'live' video.  It runs at normal speed for 1 second, then 
stops for .2 seconds or so, and repeats....  I've tried 'redefining' the 
audio device so that it doesn't even play audio (I get prompted to 
continue without audio), and the video still runs in fits and spurts.  
I've built MythTV with GL enabled, and get about 8500 fps with 
glxgears...    I've also configured the kernel for:

CONFIG_HZ_1000=y
CONFIG_HZ=1000
CONFIG_PREEMPT=y
CONFIG_PREEMPT_BKL=y

But that hasn't helped.....

I've tried different video sizes, turned interlacing on/off, chose a 
different mpeg decoding lib....  nothing seems to help.

Exactly what IS a 'prebuffering pause'?  And does anyone have any ideas 
how to 'fix' it?  What additional information can I include to help 
figure this out?